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排序方式: 共有617条查询结果,搜索用时 15 毫秒
141.
Metabolic pathways of the colonic metabolism of flavonoids (flavonols,flavones and flavanones) and phenolic acids 总被引:1,自引:0,他引:1
Aida Serra Alba Macià Maria-Paz Romero Jordi Reguant Nadia Ortega Maria-José Motilva 《Food chemistry》2012
Flavonoids are metabolized by the gut microflora giving rise to a wide range of phenolic acids that may exert systemic effects in the body. Nevertheless, the colonic metabolism pathways and the function of the metabolites formed are poorly studied. In the present study, the individual colonic metabolism of three subclasses of flavonoids (flavonols, flavones and flavanones) and phenolic acids was evaluated. For this, seven standards of flavonoids (quercetin, quercetin–rhamnoside, quercetin–rutinoside, myricetin, luteolin, naringenin and kaempferol–rutinoside) and two phenolic acids (protocatechuic acid and gallic acid) were submitted to an in vitro fermentation model using rat colonic microflora. Simultaneously, a nuts–cocoa cream enriched with these standards of flavonoids was incubated and the colonic metabolism of these compounds was evaluated. The results showed that the greatest number of colonic metabolites came from the fermentation of quercetin and quercetin–rhamnoside, and the maximum concentration of fermentation products was observed after 48 h of fermentation. On the other hand, a smaller number of fermentation products were observed after the colonic fermentation of kaempferol–rutinoside, naringenin, luteolin and myricetin. The phenolic acids were slightly metabolized by the colonic microflora. 相似文献
142.
Mohammad Norouzi Jaime Valls Miro Gamini Dissanayake 《Journal of Intelligent and Robotic Systems》2017,86(2):291-307
This paper proposes a novel path planning method for improving the feasibility of a forced landing. When an aircraft completely loses its thrust, the only measure it can take is to make a forced landing at an adjacent airport as soon as possible. In such a situation, the flight path to the landing point must be safe and viable. This paper details a method which enables safer and easier landing by transferring the benefits of excess altitude to the final approach length. Moreover, by planning the descent angle of final approach to be in the middle of a non-spoiler and a full-spoiler glide angle, this method enables a change in descent angle to correct any tracking errors, without using thrust. To verify the effectiveness of the proposed method, six degrees-of-freedom nonlinear simulations were performed and the results are compared with comparable methods. From the simulation results, it was confirmed that the proposed method could plan a safe path in a sufficiently short time and the aircraft could reach the landing point safely. 相似文献
143.
Characterization of aerodynamic performance of wind-lens turbine using high-fidelity CFD simulations
Wind-lens turbines (WLTs) exhibit the prospect of a higher output power and more suitability for urban areas in comparison to bare wind turbines. The wind-lens typically comprises a diffuser shroud coupled with a flange appended to the exit periphery of the shroud. Wind-lenses can boost the velocity of the incoming wind through the turbine rotor owing to the creation of a low-pressure zone downstream the flanged diffuser. In this paper, the aerodynamic performance of the wind-lens is computationally assessed using high-fidelity transient CFD simulations for shrouds with different profiles, aiming to assess the effect of change of some design parameters such as length, area ratio and flange height of the diffuser shroud on the power augmentation. The power coefficient (Cp) is calculated by solving the URANS equations with the aid of the SST k–ω model. Furthermore, comparisons with experimental data for validation are accomplished to prove that the proposed methodology could be able to precisely predict the aerodynamic behavior of the wind-lens turbine. The results affirm that wind-lens with cycloidal profile yield an augmentation of about 58% increase in power coefficient compared to bare wind turbine of the same rotor swept-area. It is also emphasized that diffusers (cycloid type) of small length could achieve a twice increase in power coefficient while maintaining large flange heights. 相似文献
144.
Montserrat Batet David Isern Lucas Marin Sergio Martínez Antonio Moreno David Sánchez Aida Valls Karina Gibert 《Journal of Intelligent Information Systems》2012,38(1):95-130
Home Care (HC) assistance is emerging as an effective and efficient alternative to institutionalized care, especially for
the case of senior patients that present multiple co-morbidities and require life long treatments under continuous supervision.
The care of such patients requires the definition of specially tailored treatments and their delivery involves the coordination
of a team of professionals from different institutions, requiring the management of many kinds of knowledge (medical, organizational,
social and procedural). The K4Care project aims to assist the HC of elderly patients by proposing a standard HC model and
implementing it in a knowledge-driven e-health platform aimed to support the provision of HC services. This paper focuses
on two knowledge-based personalization aspects incorporated in the platform that aim to overcome the difficulties of HC delivery.
The first one is the assistance to medical practitioners in the process of defining a customized treatment adjusted to the
medical and social conditions of a particular patient in order to consider multiple co-morbidities. The second one is the
possibility of tailoring the profiles of the care professionals according to the medical and organizational daily requirements
in order to allow a flexible care delivery. Those two aspects, guided by the knowledge explicitly represented in the platform,
play a crucial role in the medical and social acceptance of this kind of e-health systems. The paper also includes a real
case study designed and tested by healthcare professionals and includes encouraging results from the test of the platform
in a real health care environment in the city of Pollenza (Italy). 相似文献
145.
Alejandro Ogazon del Toro Lidia Jimenez Mauricio Serrano Rubi Aida Castillo Lorena Hinojosa Jacqueline Martinez Rendon Marcelino Cereijido Arturo Ponce 《International journal of molecular sciences》2021,22(11)
Prostaglandins are a group of lipids that produce diverse physiological and pathological effects. Among them, prostaglandin E2 (PGE2) stands out for the wide variety of functions in which it participates. To date, there is little information about the influence of PGE2 on gap junctional intercellular communication (GJIC) in any type of tissue, including epithelia. In this work, we set out to determine whether PGE2 influences GJIC in epithelial cells (MDCK cells). To this end, we performed dye (Lucifer yellow) transfer assays to compare GJIC of MDCK cells treated with PGE2 and untreated cells. Our results indicated that (1) PGE2 induces a statistically significant increase in GJIC from 100 nM and from 15 min after its addition to the medium, (2) such effect does not require the synthesis of new mRNA or proteins subunits but rather trafficking of subunits already synthesized, and (3) such effect is mediated by the E2 receptor, which, in turn, triggers a signaling pathway that includes activation of adenylyl cyclase and protein kinase A (PKA). These results widen the knowledge regarding modulation of gap junctional intercellular communication by prostaglandins. 相似文献
146.
Gemma Montagut Isabel Baiges Josep Valls Ximena Terra Josep M. del Bas Xavier Vitrac Tristan Richard Jean-Michel Mérillon Lluís Arola Mayte Blay Cinta Bladé Juan Fernández-Larrea Gerard Pujadas Josepa Salvadó Anna Ardévol 《Food chemistry》2009
The relationship between grape seed-derived procyanidin extract components and their bioactivity was explored. The monomeric and dimeric structures only acted as anti-inflammatory agents. Similarly, pure C1 trimer was highly effective on LPS-activated macrophages. To reproduce all of the bioactivities of the total extract, a fraction enriched with trimeric structures was needed. This trimeric-enriched fraction was divided into subfractions, the most bioactive of which contained two compounds with a molecular weight equal to a trimer (865) and a dimer-gallate (729), according to spectrometric analysis. Thus, it may be concluded that a mixture of both molecules reproduces the bioactivity in glucose metabolism (3T3-L1), lipid metabolism (HepG2) and macrophage functionality (RAW 264.6). 相似文献
147.
148.
A flow-through apparatus with a microtube-reactor has been developed for rapid and continuous hydrothermal synthesis. Heat-up time of starting solution to 523 K is within 0.08 s and this promises rapid nucleation of nanoparticles compared with conventional batch reactor. Continuous production of Ag, Fe2O3, TiO2, and ZrO2 particles from metal salts aqueous solution was performed at 523 K and 30 MPa with the reactor. Nanoparticles having an average particle size and a coefficient of variation less than 5.4 nm and 0.22 could be continuously obtained. 相似文献
149.
C.E. Benouis M. Benhaliliba F. Yakuphanoglu A. Tiburcio Silver M.S. Aida A. Sanchez Juarez 《Synthetic Metals》2011,161(15-16):1509-1516
Here, we report on the preparation and characterization of nanosized indium doped tin oxide films (TO:In). The films are grown by ultrasonic spray pyrolysis deposition (USPD) onto glass. The structural, optical, electrical and morphological properties of SnO2 (TO) films are investigated. The as-deposited films SnO2 have preferred orientation along the (2 0 0) plane and are polycrystalline with a tetragonal crystal structure. Following this direction, the average grain size, obtained from XRD patterns, decreases with the rate doping. It ranges from 64 to 17 nm. In UV spectrum, the transmittance increases followed by a slight decay within visible range. Optical band gap, Eg, is about 4.1 eV. The samples reveal a high resistivity which varies in the range 104–107 Ω cm. Activation energies of shallow levels, as obtained from Arrhenius plots, vary from 85 meV to 165 meV. SEM and AFM analysis demonstrate nanostructure morphology. 相似文献
150.
Journal of Dynamical and Control Systems - We classify the phase portraits in the Poincaré disc of the differential equations of the form $x^{\prime } = -y + x f(x,y)$ , $\dot y =x + y f(x,y)$... 相似文献